IL-4 and IL-10 inhibition of IFN-gamma- and TNF-alpha-dependent nitric oxide production from bovine mononuclear phagocytes exposed to Babesia bovis merozoites. |
| |
Authors: | W L Goff W C Johnson S M Parish G M Barrington T H Elsasser W C Davis R A Valdez |
| |
Institution: | Animal Disease Research Unit, USDA-ARS, Washington State University, 3003 ADBF, P.O. Box 646630, Pullman, WA 99164-6630, USA. wgoff@vetmed.wsu.edu |
| |
Abstract: | The requirement for IFN-gamma and/or TNF-alpha as co-stimulants with Babesia bovis merozoites for nitric oxide (NO) production was examined, as well as the regulatory role of IL-4 and IL-10. Purified B. bovis merozoites did not induce the production of NO in undifferentiated monocytes without addition of exogenous IFN-gamma and TNF-alpha unless the monocytes taken ex vivo were producing TNF-alpha endogenously. Under the latter condition, the NO production resulting from merozoite stimulation remained IFN-gamma-dependent. There was no evidence for endogenous synthesis of TNF-alpha in monocyte-derived macrophages (MDM), and merozoites alone were incapable of inducing TNF-alpha mRNA in MDM. However, while merozoites plus IFN-gamma induced TNF-alpha mRNA expression in MDM, NO was not produced. Both IL-4 and IL-10 inhibited expression of iNOS and production of NO in merozoite-stimulated monocytes. |
| |
Keywords: | |
|
|